The manual describes the culture of groupers (Epinephelus) in floating cages, providing a farming option for grouper growers and also a production alternative to the farmed species being done today, such as shrimp, milkfish and tilapia. The following aspects are covered: species identification for commercially cultured groupers; source of stock; net cage specifications; anchor; hides and shelters; nursery net cage operation; production cages; harvesting; post-harvest; profitability analysis of grouper cage culture; and, cost and return of growing grouper in cages

Baliao, Dan D.

delos Santos, Miguel A.

Franco, Nilo M.

Jamon, Neil Raphael S.

English

Southeast Asian Fisheries Development Center, Aquaculture Department Institutional Repository (SEAFDEC/AQD Institutional Repository )

SEAFDEC/AQD Institutional Repository (SAIR)This document is downloaded at: 2013-07-02 06:50:06 CSTTitle Grouper culture in floating net cages.Author(s) Baliao, Dan D.; delos Santos, Miguel A.; Franco, Nilo M.; Jamon, NeilRaphael S.CitationBaliao, D. D., delos Santos, M. A., Franco, N. M., & Jamon, N. R. S.(2000). Grouper culture in floating net cages. Tigbauan, Iloilo, Philippines:Aquaculture Department, Southeast Asian Fisheries Development Center.Issue Date 2000URL http://hdl.handle.net/10862/1543http://repository.seafdec.org.phAQUACULTURE EXTENSION MANUAL NO. 29 JANUARY 2000Grouper culturein floating net cagesDD Baliao, MA delos Santos, NM Franco, NRS JamonAQUACULTURE DEPARTMENTSoutheast Asian Fisheries Development CenterTigbauan, Iloilo, PhilippinesAQUACULTURE EXTENSION MANUAL NO. 29JANUARY 2000Grouper culturein floating net cagesDan D. BaliaoMiguel A. delos SantosNilo M. FrancoNeil Raphael S. JamonAQUACULTURE DEPARTMENTSOUTHEAST ASIAN FISHERIES DEVELOPMENT CENTERTigbauan, Iloilo, PhilippinesGROUPER CULTURE IN FLOATING NET CAGESJANUARY 2000ISBN 971-8511-39-3Published and printed by:Aquaculture DepartmentSoutheast Asian FisheriesDevelopment CenterTigbauan, Iloilo, Philippines© Copyright 2000Aquaculture DepartmentSoutheast Asian FisheriesDevelopment CenterTigbauan, Iloilo, PhilippinesALL RIGHTS RESERVEDNo part of this publication may bereproduced or transmitted in any form orby any means, electronic or mechanical,including photocopy, recording, or anyinformation storage and retrieval system,without the permission in writing from thepublisher.For commentsand inquiries: Training and Information DivisionSEAFDEC Aquaculture DepartmentTigbauan, Iloilo 5021, PhilippinesFax (63-33) 335 1008, 336 2891E-mail tid@i-iloilo.com.ph/tvp@aqd.seafdec.org.ph/AQD website http//www.seafdec.org.ph/FOREWORDAQD’s manuals are end results of verification studies conducted infarms in consideration of profit. Usually, the studies that are verified infarms are first conducted in controlled conditions to investigate a par-ticular problem using the scientific method. In turn, the actual farmstudies show the viability and profitability of such studies, thus, themanuals are instructional and production oriented.AQD’s verification activities are conducted by the Technology Verifi-cation and Extension Section. Since the section was created in 1996,manuals on grouper in brackishwater ponds, mudcrab, and milkfishhave been published.This volume on grouper in floating cages gives a farming option forgrouper growers. It is also a production alternative to the farmed spe-cies being done today such as shrimp, milkfish, and tilapia.AQD appreciates the cooperation of farmers who collaborated in thisproject. We hope this volume would start the development of options offish producers who are in search of aquaculture alternatives.ROLANDO R. PLATON, PhDChief, SEAFDEC Aquaculture DepartmentCONTENTSForeword iiiSpecies identification for commercially cultured groupers 1Source of stock 2Net cage specifications 3Anchor 4Hides and shelters 5Nursery net cage operation 5Production cages 5Harvesting 6Post harvest 6Profitability analysis of grouper cage culture 6Cost and return of growing grouper in cages 8References 10A design of a floating cage for grouper cultureGrouper culturein floating net cagesGrouper (Epinephelus spp.) locally known as inid or lapulapu has beencultured in net cages, and to some extent in ponds in Southeast Asia formore than a decade. Valued for the excellent texture and flavor of itsflesh, this finfish species has great potential in aquaculture. The de-mand for grouper in the international market is fast growing particu-larly in Hongkong, Japan, and Singapore. Its export price is expected toincrease in the near future. Culture of grouper could therefore becomeanother dollar earner for the country.Species identification for commercially cultured groupersThere are about 40 species of grouper distributed in tropical waters and2 species are popularly cultured commercially at the present time.Epinephelus coioides(Hamilton, 1822)Common name:Orange spottedgrouperLocal name:Inid or lapulapu(Ilonggo)Distinguishing char-acteristics: Body coloris light yellowish-brown dorsally, shad-ing to whitish on the side and belly, numerous brownish-orange orbrownish-yellow with unequal sized spots scattered on the head, body,and fins. The chin or underside of head and belly is whitish or creamywhite without spots.Epinephelus malabaricus (Block and Schneider)Common name: Black spotted grouperLocal name: Inid or lapulapu (Ilonggo)Distinguishing characteristics: Body color is light brown on the upperpart of the body, belly and ventral side light gray; body with 5 distinctbroad dark brown oblique barswhich tend to bifurcateventrally. Head andbody with numeroussmall, wellseparatedblack spotsespeciallyon chin; finsscatteredwith smallblack spots.Source of stockAt present, supply of grouper fry for commercial cage/pond productionis still dependent from the wild. Grouper fry is collected in nominalquantity using various devices e.g., scare lines or brush piles. The sizeof the fry varies from 1 to 9 cm and are usually collected by fish trapfrom coastal waters near mangrove areas. In the Philippines, the majorsources of grouper fry include provinces of Pangasinan, Cavite,Mindoro, Quezon, Masbate, Bulacan, Cagayan, Dadiangas, Zam-boanga del Sur, and Negros Occidental.Dependence of fry or fingerlings from wild source for stocking are stillbeing resorted to pending refinement of broodstock and seed produc-tion technique being done by R & D institutions like SEAFDEC/AQDor other progressive finfish hatchery operators elsewhere.Classification of grouper seedstock for pond and net cagesBL (cm) BW (g) Price (P—/pcs)Fry 1-2 1-3 6-8Fry 1 3-4 4-5 8-10Fry 2 5-7 6-9 15-20Fry 3 8-9 10-13 25-30XL 1-12 15-24 45-65Undersize 13-20 30-160 55-75Goodsize 30-70 400-700 260-280BL - Body lengthBW - Body weight2 Grouper culture in floating net cagesSITE SELECTIONNet cages should be set up in calm waters, e.g., sheltered lagoons,coves, inlets, bay, behind an island or a river mouth. This will avoiddamage caused by strong waves and current.Area should be protected from strong winds, waves, and current. Anideal area would be a protected bay, sheltered cove or inland sea.Salinity should range between 20-34 pp.Water depth should be not less than 3 meters during lowest low tide.Site should have good water exchange to maintain good water quality.Site must be relatively free from any source of pollution (industrial, ag-ricultural, and domestic) and protected from environmental hazardssuch as typhoons, floods, erosions, etc. It must be accessible and pref-erably secure from vandals and poachers.Site should be situated in areas where supply of trash fish is cheap andabundant.Grouper culture in floating net cages 3Net cage specificationsA floating cage module usuallyhas 4 to 12 compartments sup-ported by a framework.In constructing a floating net cagemodule the following should beconsidered:Cage frame – made of galva-nized iron pipe, wood or bamboo.Construction should be durableenough to withstand stress causedby wave action and increasedweight during the culture period.Dimension - 5m x 5m x 3mSinkers – Concrete blocks, plas-tic containers filled with sand,and galvanized pipes are used assinkers suspended by ropes,placed to the bottom of four cor-ners of the net cage for rigging.Flotation materials – Plasticdrums or empty plastic containers(20 liter capacity). Four pieces4 Grouper culture in floating net cagestied together used as floats are placed on each side of the cage betweenthe two pipes or bamboos (3 on each side). To prevent the floaters fromdrifting especially when the module is subjected to strong wave action,the floaters should be securely tied to the cage frame using a rope 5 mmin diameter.CAGE NETTINGNursery net; “B” net (0.5 to 1 cm mesh size; knotless).Production net; “PE” net (2 to 5 cm mesh size).Nets are fabricated like inverted mosquito nets. Each net cage is sup-ported with polyethylene rope (5 mm diameter) inserted along thesewed portion of the net and held together using a clove hitch withoverhand knot.Each cage should have layered nets to avoid loss of stock due to tearingand other mechanical damages.AnchorThe rope length from the float to the anchor should be the same as thewater depth at high water spring tide (HWST). The raft structure needs14 concrete blocks (0.5 to 1 ton each), 8 being placed at the ebb end(ebb tide being stronger than the flood tide) and four at the flood endwith two in the mid section.Generally, the weight of the anchor should be 2 times the weight of theentire floating cage module.Check and mend nets of floating cages regularly.Hides and sheltersSawed off bamboos or PVC pipes, 5 cm in diameter and 15 cm in length(for grow-out cages) tied in triangular bundles @ 10 pcs/bundle) andsunken in strategic areas inside the net cage.Nursery net cage operationNursery net cages are necessary when fry of size 2 to 10 cm total length(TL) are the only ones available.Sorting should be done every three days to separate the shooters (biggersized; more than 10 cm) and prevent cannibalism. The shooters may bestocked directly in production net cages. Utmost care in handling thefry should be strictly observed to minimize stress and mortality aftersorting operationStocking rate: 10 to 20 fish/m3. Feeds include mysid shrimps or finelychopped trash fish given at the rate of 10% of the total body weight.Feeds are divided and given two to four times daily.Install 50 W incandescent lamp (hover type) inside the cages about halfa meter above the water line at night to attract live food (mysids, copep-ods, and other young fishes).Production net cagesProduction net cages are necessary when stock size available are morethan 10 to 15 cm TL.Grouper culture in floating net cages 5Hides (left); incandescent lamp placed above the cages attract live foodsuch as mysids, copepods, and other young fish (right).Stocking rate: 10 to 20 fish/m3. Chopped trash fish are given at a rate of5% of the total body weight. Feeds are divided and given two timesdaily.Monitor pH, dissolved oxygen, salinity and water temperature twice aweek.Sample stock every 15 days to determine feed requirement and growthrate of grouper stocks.Procedure for sampling is by scooping 10 to 15 samples and measuringits weight and length.Inspect nets for leakage. Clean/remove dirt, debris and fouling organ-isms attached on nets. Repair/replace damaged net. Change nets at leastonce a month.HarvestingHarvest depends on the demand of the local and export market. It isnormally done towards the end of the culture period. Fish are harvestedby lifting the net. Care must be taken not to excite and damage the fish.They are not given feeds a day prior to harvest.Post harvestScoop live, marketable size grouper (more than 400 g) from net cages.Hold grouper temporarily inside the conditioning tank and provideaeration for about one to two hours. Adjust water temperature graduallyto 18°C by adding packed ice. Place 3 to 5 fishes inside double-sheetplastic bags, oxygenated, and with water of 3 to 5 cm or at least cover-ing the nostrils of the fish. Crushed ice are placed on top of the plasticbags to maintain coolness of water during transport. Place plastic bagsinside the square styrofoam box (30 x 30 x 20 cm) with the carton coverhaving a tag “live fish.” These are then ready for transport.Profitability analysis of grouper cage cultureThere are some important considerations for converting grouper cultureinto a highly profitable business, namely: survival and growth rates, ad-equate and cheap supply of raw meat i.e., trash fish and mollusk meat,quantity/quality seedstocks, and marketing.Actual nursery operations in SEAFDEC/AQD reveal that survival rateof 79% from tiny to XL can be achieved, and this is about 20% higherthan the rate used in this profitability analysis. Proper care of the frycan significantly result in reducing cost of operation.6 Grouper culture in floating net cagesAbundant and cheap supply of trash fish, cockles, or brown musselshould be ascertained as this constitutes the biggest chunk in operatingexpenses. Higher price for these feeds would significantly reduce theprojects’ profitability.The most important consideration before venturing into grouper cul-ture is the availability of buyers or exporters who would purchase theproduct.Grouper culture in floating net cages 7Manual handling of live grouper immediately from a netcage, (top); livegrouper being readied for transport in styropore boxes, (bottom).8 Grouper culture in floating net cagesGroupers are popular food fish in many specialty restaurants when theyweigh 400g or more.Cost and return of growing grouper in cagesOne crop, one moduleTECHNICAL DATASize of net cage 5m x 5m x 3mTotal number of net cages/module 6 unitsStocking rate per net cage 500 pcsSize of initial stock 2.5 to 3 inchesTotal number of stocks in one module 3,000 pcsCulture period 5 to 7 monthsSurvival rate 80%Average body weight at harvest 450 gramsCroppings per year 1Total harvest 1,080 kilogramsSelling price P— 280.00Feed conversion ratio 5 is to 1INVESTMENT REQUIREMENTQuantity Unit Cost Total CostBamboo poles, big sizes 80 pcs  P— 30 P— 2,400.00Nylon nets, 1/2 inch mesh size 5 rolls 1,500.00 7,500.00GI pipes, 1 in diameter, 5 m long 24 pcs 100.00 2,400.00GI elbow, 1 in diameter 24 pcs 30.00 720.00Plastic container, 20 l capacity 105 pcs 55.00 5,775.00Mononylon twine # 120 15 kgs 150.00 2,250.00Evelon Cord #9 (4.5 mm) 2 rolls 200.00 400.00Anchors and rope 4 pcs 500.00 2,000.00CW nails 2 kgs 50.00 100.00Netting needle 3 pcsLabor for cage construction 7,000.00Grouper fingerlings 3,000 22.00 66,000.00Feeds 5,400 kgs 10.00 54,000.00Wages of one caretaker/feeder 8 mo 4,000.00 32,000.00Caretaker’s hut 5,000.00TOTAL INVESTMENT REQUIREMENT P— 187,545.00ANNUAL OPERATING COSTSGrouper fingerlings 66,000.00Wages of caretaker 32,000.00Feeds 54,000.00Depreciation of cages and hut 11,848.00Repairs and maintenance @ 3% 1,066.00Interest @ 14% 26,256.00TOTAL OPERATING COSTS P— 191,170.00ANNUAL INCOME 302,400.00NET PROFIT 111,230.00BREAK EVEN VOLUME (BEV) 684 kgBREAK EVEN SELLING PRICE (BESP) P— 177/kgRETURN ON INVESTMENT 59%PAYBACK 1.68 yearsGrouper culture in floating net cages 910 Grouper culture in floating net cagesReferencesBagarinao TU, NB Solis, WR Villaver, and AC Villaluz. 1986. Impor-tant fish and shrimp fry in Philippine coastal waters: identification, col-lection, and handling. Aquaculture Extension Manual No.10,SEAFDEC Aquaculture Department. Tigbauan, Iloilo, Philippines. p.18Boonyaratpalin S, K Supamattaya, I Kasorn Chandra and RW Hoffman.1996. Picornia-like virus associated with mortality and a spongious en-cephalopathy in grouper Epinephelus malabaricus. Dis. Aquat. Org. 26:75-80.Cox R. 1998. The gango: an ecologically sustainable tropical reef fishnursery? Aust Asia Aquaculture: 12(1): 8-9.Heemstra PC and JE Randall. 1993. FAO Species Catalogue, Vol. 16Groupers of the World, Food and Agriculture Organization, Rome.382 p.Kasornchandra J and R Khongpradit. 1996. Isolation and preliminarycharacterization of a pathogenic iridovirus-like agent in nursing grou-per, Epinephelus malabaricus. The 1996 Annual Meeting of the WorldAquaculture Society. Bangkok. p.194.Kohno H, M Duray and J Juario. 1988. State of grouper culture in thePhilippines. SEAFDEC Asian Aquaculture 10 (1):4-8.Lavilla-Pitogo CR, AR Castillo, and MC de la Cruz. 1992. Occurrenceof Vibrio sp. infection in grouper Epinephelus suillus. Journal of Ap-plied Ichthyology 8:175-179.Leong TS and SY Wong. 1990. Parasites of healthy and diseased juve-nile grouper (Epinephelus malabaricus) and seabass (Lates calcariferBloch) in floating cages in Penang, Malaysia. Asian Fisheries Science3:319-327.Rimmer M. 1997. Grouper aquaculture in Australia: industry study es-tablishes its feasibility. Aquaculture Asia, April-June 1997. p 39.Subasinghe S. 1987. Live fish – handling and transportation.INFOFISH International Vol. 2. p. 39-43.Toledo JD, A Nagai, and D Javellana. 1993. Successive spawning ofgrouper Epinephelus suillus (Valenciennes) in a tank and a floating netcage. Aquaculture 115:361-367.Weston DP. 1986. The environmental effects of floating mariculture inPuget Sound. School of Oceanography, WB-10. University of Washing-ton, Seattle, Washington. 148 pp.About SEAFDECThe Southeast Asian Fisheries DevelopmentCenter (SEAFDEC) is a regional treaty orga-nization established in December 1967 topromote fisheries development in the region.Its Member Countries are Japan, Malaysia,the Philippines, Singapore, Thailand, BruneiDarussalam, and the Socialist Republic ofViet Nam.Representing the Member Countries is theCouncil of Directors, the policy-makingbody of SEAFDEC. The chief administratorof SEAFDEC is the Secretary-Generalwhose office the Secretariat, is based inBangkok, Thailand.Created to develop fishery potentials in theregion in response to the global food crises,SEAFDEC undertakes research on appropri-ate fishery technologies, trains fisheries andaquaculture technicians, and disseminatesfisheries and aquaculture information. Fourdepartments were established to pursue theobjectives of SEAFDEC.• The Training Department (TD) in SamutPrakan, Thailand, established in 1967 formarine capture fisheries training• The Marine Fisheries Research Depart-ment (MFRD) at Changi Fisheries Com-plex, Singapore, established in 1967 forfishery post-harvest technology• The Aquaculture Department (AQD) inTigbauan, Iloilo, Philippines, establishedin July 1973 for aquaculture research anddevelopment• The Marine Fishery Resources Develop-ment and Management Department(MFRDMD) in Kuala Terengganu, Malay-sia, established in 1992 for the develop-ment and management of the marine fish-ery resources in the exclusive economiczones (EEZs) of SEAFDEC Member-Countries.

Grouper aquaculture in Australia: industry study establishes its feasibility. Aquaculture Asia, April-June

Important fish and shrimp fry in Philippine coastal waters: identification, collection, and handling. Aquaculture Extension Manual No.10, SEAFDEC Aquaculture Department.

Isolation and preliminary characterization of a pathogenic iridovirus-like agent in nursing grouper, Epinephelus malabaricus. The

Live fish – handling and transportation.

Occurrence of Vibrio sp. infection in grouper Epinephelus suillus.

Parasites of healthy and diseased juvenile grouper (Epinephelus malabaricus) and seabass (Lates calcarifer Bloch) in floating cages in Penang,

State of grouper culture in the Philippines.

Successive spawning of grouper Epinephelus suillus (Valenciennes) in a tank and a floating net cage.

The environmental effects of floating mariculture in Puget Sound. School of Oceanography, WB-10.

The gango: an ecologically sustainable tropical reef fish nursery?

Grouper culture in floating net cages

Grouper culture in floating net cages

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Southeast Asian Fisheries Development Center, Aquaculture Department Institutional Repository (SEAFDEC/AQD Institutional Repository )